Grain boundaries in YBa2Cu3O7-delta films grown on bicrystalline Ni substrates

Abstract

In order to investigate the alternating transport properties introduced by individual grain boundaries of rolling assisted biaxially textured substrate based YBa2Cu3O7-delta (YBCO) coated conductors, the growth of well defined bicrystalline films on buffered metallic substrates is desirable. Bicrystalline YBCO films were successfully prepared on Ce0.9Gd0.1O1.95 (CGO) buffered bicrystalline Ni foils. The Ni foils are grown epitaxially on a KCI bicrystal, The optimum conditions of epitaxial growth for each layer and the superconducting properties of the YBCO films were determined. A similar to 6 degrees [0 0 1] tilt grain boundary was investigated in more detail. We succeeded to grow an epitaxial CGO single buffer layer with a full width at half maximum of only 3.50. The YBCO films grew perfectly epitaxially and showed good superconducting properties like a T-onset of 88 K, a j(c) of 1.4 x 10(7) A/cm(2) in the undisturbed sections of the film and 1 x 10(6) A/cm(2) across the grain boundary (5 K, 5 mT). (C) 2001 Elsevier Science B.V. All rights reserved.